When Margaret Hilda Thatcher, née Roberts, became leader of the Conservative party just before her fiftieth birthday in 1975, few people could have anticipated the impact she would subsequently have on British society. At the time most British people knew her above all as the education minister in Edward Heath’s government who had withdrawn the free milk that until then had been given out to schoolchildren. The Sun – the newspaper that was later to be her biggest supporter in the media and whose working-class readers were the key to her spectacular electoral success – called her the most unpopular woman in Britain.

Mrs. Thatcher’s sheer longevity as prime minister – she would win three successive elections and remain in office for 11 years, making her the longest serving British prime minister of the twentieth century – was surprising enough. But perhaps even more unexpected was the nature of the economic and social revolution that would take place in the eighties and come to be identified with her. In fact, much of what later came to be known as “Thatcherism” was the opposite of what one might have expected from the woman who became Britain’s first female prime minister 30 years ago this month.

Few, for example, could have anticipated that the daughter of a Lincolnshire grocer who had emerged in British politics as the embodiment of housewifely thrift would unleash an era of casino capitalism and credit-fuelled conspicuous consumption. That era would continue into the Blair and Brown years and may only now, after the shock of the current financial crisis, be coming to an end.

Before she came to power and even for some years afterwards, Mrs. Thatcher was also considered to be more pro-European than many of her Conservative colleagues and certainly more pro-European than the Labour party – at that time euroscepticism was predominantly a left-wing stance. And yet during her time in power, she increasingly became a symbol of British opposition to European integration. Indeed, in many ways, the overall effect of what became “Thatcherism” – in reality an improvised, contradictory ideology that shifted over time – was to move this island a little further away from continental Europe and a little closer to the United States.

When Margaret Thatcher took over from the deposed Labour prime minister James Callaghan in May 1979, she wanted above all to reverse Britain’s national decline or, as she endlessly put it, make Britain great again. By the middle of the 1970s, the slow post-war loss of Britain’s imperial role as “workshop of the world” had left it with a failing economy of unprofitable industries and high inflation. In 1976 Britain was forced to devalue the pound and ask the IMF for a loan, which West Germany helped to fund. In fact, at that time, the Federal Republic rather than the United States was the model for many in Britain: it seemed that we had won the war but lost the peace. For many voters, the last straw was the so-called “winter of discontent” in 1978, during which, as a result of public sector strikes, rubbish piled up on the streets and hospitals turned away patients.

Many people (including some within New Labour) believe that Thatcher almost single-handedly succeeded in reversing this national decline. However, the economic reforms later associated with Thatcher by her opponents as well as her supporters had already been anticipated by Callaghan, who had for example begun to sell council houses to their tenants. Moreover, many of the changes Thatcher made were forced by long-term and global changes over which no British government had any control. “There were huge changes [under Thatcher], but they were not running against the tide of history,” says historian Dominic Sandbrook. Nor was the Thatcherite response either immediate nor expected. In fact, Sandbrook points out, there was no mention of deregulation – later the central plank of Thatcherite economic policy – in the Conservative manifesto on which Mrs. Thatcher was elected in 1979.

There is little doubt, however, that Thatcher accelerated the process of economic liberalisation in the eighties that transformed the British economy. While Sandbrook says there is little evidence that Margaret Thatcher had herself read the liberal economic theorists she claimed as influences – above all Adam Smith, Friedrich Hayek and Milton Friedman – she was guided by others around her like Keith Joseph, her policy guru, who had. Under their influence, the City of London was deregulated, exchange rate controls were relaxed and a total of 13 state-owned enterprises were privatized in her first ten years in power. One result was an explosive growth in retail stock trading (which Thatcher’s father, who she always claimed as an influence, saw as a form of gambling, as Germaine Greer has recently pointed out).

The bloodiest front in the Thatcherite revolution was the battle with the trade unions. Throughout the seventies, the trade unions, particularly those in manufacturing industry, had helped to keep prices high and stop innovation and ultimately defeated both Heath and Callaghan. Thatcher took them with a ferocity neither of her predecessors had, culminating in the brutal miners’ strike of 1984-5. Many on the British left believe Thatcher destroyed manufacturing industry in Britain. However, according to Sandbrook, she simply “turned off the life support system” to unprofitable industries such as coalmining. Although some sectors of manufacturing industry like aerospace thrived in the eighties, much of the new growth in the economy would come from services, especially financial services.

The effects of this economic revolution on British people’s lives were complex and different for different sections of the population, which is one of the reasons why Thatcher still polarizes British public opinion so much even now. For example, while things got dramatically worse for much of the unskilled lower working class, they got better for a section of the skilled upper working class – as well as being able to buy a home, it became easier to get credit and start a business. This split also had a geographic dimension. Whole communities in the north of England and in Wales and Scotland, where industries such as coalmining were concentrated, were devastated. But a new property-owning working class emerged – particularly in the south-east of England, which happened to also be where many marginal parliamentary seats were concentrated – that became the core of Thatcher’s electoral success. It had more money to spend and more to spend it on: it was above all in the eighties that shopping took over as our main leisure pursuit.

This fragmentation of the traditional working class may have been part of the reason why the class system loosened in the 1980s – probably one of the most profound changes in British life associated with Thatcher. Britain had already become less hierarchical and deferential since the 1960s but became even more so under Thatcher, who was herself lower middle-class and liked to surround herself with self-made businessmen. Sandbrook says birth and breeding didn’t cease to matter but they did “lose their grip” in the eighties – another way in which Britain became more American under Thatcher.

Unemployment continued to increase after 1979, reaching two million in 1980 and three million 18 months later. But during the Thatcher years, the rest of us apparently learned to live with it. “Thatcher sold to people the idea that there was no helping the poor,” says Sandbrook. “It wasn’t society’s responsibility. It was just life.” Richard Vinen, professor of modern European history at King’s College, London, and author of the recently published Thatcher’s Britain, suggests that the unemployed became increasingly invisible: from the eighties onwards, the inflation rate would come to be considered more important than the unemployment rate.

Perhaps almost as important as the economic changes that happened under Thatcher was the renewed sense of national pride that animated the new era of credit and consumption. While Thatcher’s economic policies created a more unequal society, Sandbrook says she was nevertheless successful in creating a sense – whether real or imagined – that the days in which Britain had been the sick man of Europe was over. “She changed the background and the soundtrack,” says Sandbrook.

The turning point in this mood change may have been the Falklands war as much as anything that happened in the economy. Thatcher had always said that Winston Churchill was her inspiration, and nowhere was his influence more real than in the resolution she displayed in responding to the Argentinian invasion of the Falklands islands in 1982. The war, which was nearly a disaster but ultimately successful, added a new dimension to Thatcher’s political persona – that of Elizabethan warrior queen – and helped her win the 1983 election with an increased majority. For many voters, she had, like Reagan in America, restored a kind of national pride. After the war, Vinen says, Britain felt like “a nasty country but a powerful country, rather than a nasty but weak country”.

Thirty years after Margaret Thatcher came to power, there is still little consensus about how the combination of economic liberalism and social conservatism for which she came stand changed Britain. Perhaps the most difficult question of all to answer is what effect Thatcher had on women’s lives. Germaine Greer wrote recently that Thatcher was a “man’s woman” who married a millionaire and did little for her own gender (few women served in her cabinet, for example). But historians agree that although Thatcher distanced herself from feminism, she had huge symbolic power as the first woman to occupy Britain’s highest office. That may even turn out to be Margaret Thatcher’s most profound and lasting legacy for British life.

A version of this article appeared in German in Der Freitag.